Anatomy is the study of body structure while physiology is the study of body functions. The human body is organized in multiple levels from atoms and molecules to cells, tissues, organs and organ systems. Homeostasis refers to maintaining equilibrium in the internal environment through feedback mechanisms. Anatomy and physiology provide a foundation for understanding health and disease.

1. HUMAN ANATOMY AND PHYSIOLOGY
AN INTRODUCTION
Dr. Nitin Kumar Sen
Department of pharmacology
SJIPR, Palghar

2. Learning objectives
What is the difference between anatomy and physiology?
What are the different levels of organization?
What differentiates living things from non-living things?
What is homeostasis?
What are the components of a feedback mechanism?
Explain anatomical body positions, directional terms used for
location of a body organ in relation to other organs?

3. Anatomy and Physiology
◆Anatomy is the study of body structure.
science of structure
◆Physiology is the science of body functions.
science of body functions

4. Structure mirrors function
• This structure is the liver, which has the function of filtering blood and
producing bile. Can you see how the function is determined by the structure,
and vice versa?

5. Surface Anatomy is the study of form and markings of the
body surface, often explored through visualization or palpation
(without any “cutting”).
Gross Anatomy is the study of anatomical structures visible to
unaided eye.
After making the appropriate surface marking in the prior
picture, the gross dissection proceeds through “cutting.”
Subdivisions of Anatomy

6. Gross Anatomy can be studied by two general
approaches:
Systemic approach (Systemic Anatomy):
Regional approach (Regional Anatomy)

7. • Developmental anatomy
is the study of the fertilized
egg developing into its adult
form.( For e.g., Embryology)

8. Clinical Connection
An autopsy is a postmortem (after death) examination of the
body and internal organs performed by a pathologist.

9. Levels of Organization

10. Levels of Organization
The chemical level of organization
Atoms
Molecules
The Cell is next in complexity, in fact many billions of
times more complex than molecules.
Cells (and this is important!) are the basic
structural and functional units of an organism .

11. Tissues are groups of cells that work together to perform a
• similar function.
Epithelium
Connective Tissue
Muscle
Nerves

12. Levels of Organization
• Organs are structures composed of two or more different
types of tissues (all but the simplest of organs have all 4
basic tissues represented.)
•Organ systems work cooperatively to perform necessary
life functions.

13. O
2
CO2
Digestive system
Via the blood, distributes oxygen and nutrients
to all body cells and delivers wastes and carbon
dioxide to disposal organs
Interstitial fluid
Nutrients
Nutrients and wastes pass between
blood and cells via the interstitial
fluid
Integumentary
system
Protects the body as a whole
from the external environment
Feces Urine
CO2
Urinary system
O2Eliminates nitrogenous
wastes and excess ions
Takes in nutrients, breaks them down,
and eliminates unabsorbed matter (feces)
Food
Cardiovascular system
O2
Respiratory system Takes in
oxygen and eliminates carbon
dioxide
CO2
Levels of Organization
System Level

14. Levels of Organization
An organism consists of a collection of organ systems.
Six important life processes:
Metabolism
Responsiveness
Movement
Growth
Differentiation
Reproduction
In health, all parts of the body must be functioning
together in a process called homeostasis.

15. Levels of Organization
1. Metabolism: All chemical reactions that occur in body cells
▪ Catabolism and anabolism
2.Responsiveness: The ability to sense and respond to stimuli
▪ Withdrawal reflex
3.Movement (contractility)
▪ Of body parts (skeletal muscle)
▪ Of substances (cardiac and smooth muscle)
4. Growth: Increase in size of a body part or of organism

16. 4.Reproduction:
▪ Cellular division for growth or repair
▪ Production of offspring
• 6. Differentiation is the development of a cell from an
unspecialized to
specialized state. Cells have specialized structures and
functions that differ from precursor cells.

17. Survival Needs
1. Nutrient
Chemicals for energy and cell building
Carbohydrates, fats, proteins, minerals, vitamine
2. Oxygen
Essential for energy release (ATP production)
3. Water
Most abundant chemical in the body
Site of chemical reactions
4. Normal body temperature
Affects rate of chemical reactions
5. Appropriate atmospheric pressure
For adequate breathing and gas exchange in the lungs

18. Homeostasis
• A condition of equilibrium (balance) in the body’s
internal environment. It is a dynamic condition meant
to keep body functions in the narrow range compatible
with maintaining life.

19. Homeostasis
Body fluids are defined as dilute, watery solutions
• containing dissolved chemicals inside or outside of the cell.
Maintaining the volume and composition of body fluids is important.
Intracellular Fluid (ICF) is the fluid within cells
Extracellular Fluid (ECF) is the fluid outside cells
• Interstitial fluid is ECF between cells and tissues

20. Homeostasis
Cellular function depends on the regulation of the
• composition of the interstitial fluid.
Composition of interstitial fluid changes as substances
• move between plasma and the interstitial fluid.
Movement back and forth across capillary walls provides nutrients
(glucose, oxygen, ions) to tissue cells and removes waste (carbon
dioxide).

21. Homeostasis
Control of homeostasis is constantly being challenged by:
Physical insults such as intense heat or lack of oxygen
Changes in the internal environment such as a drop in blood glucose
due to lack of food
Physiological stress such as demands of work or school

22. Feedback System
Cycle of events:
Body is monitored and
re- monitored.
Each monitored variable is
termed
• a controlled condition.
Three basic components:
Receptor
Control center
Effector

24. Feedback System
Negative Feedback systems:
Reverses a change in a controlled condition
Regulation of blood pressure
Positive Feedback systems:
Strengthens or reinforces a change in one of the body’s
controlled conditions
Normal child birth

25. Feedback System
Blood Pressure regulation is
a negative feedback system.

26. Feedback System
Childbirth is an example of a positive feedback system:

27. Clinical Connection
Diagnosis of Disease is done by assessing:
Signs and symptoms
Medical history
Collecting information about event
Present illnesses and past medical problems
Physical examination:
Orderly evaluation of the body and its function
Noninvasive techniques and other vital signs (pulse)

28. Anatomical Terminology
Anatomical Position
In the anatomical position, the
subject stands erect facing the
observer with the head
• level, the eyes facing forward,
feet flat on the floor directed
forward, and the arms at their
sides, palms forward.
All anatomical descriptions are in
reference to this position.

29. Anatomical Terminology
Directional Terms
Superior
▪ Above, top, toward head
Inferior
▪ Below, bottom, away from head

30. Anatomical Terminology
Directional Terms
Anterior (Ventral)
Posterior (Dorsal)

31. Anatomical Terminology
Directional Terms
Superficial Towards the surface
DeepTowards the core of the body

32. Anatomical Terminology
Descriptive Terms
Visceral Pertaining to a covering over an organ
Parietal Pertaining to a covering against a cavity wall
Parietal
Visceral

33. Regional Names
Cranial
Cervical
Cubital
Carpal
Patellar
Orbital
Thoracic
Inguinal
▪ Skull
▪ Neck
▪ Elbow
▪ Wrist
▪ Front of knee
▪ Eye
▪ Chest
▪ Groin
Anatomical Terminology

34. Body Planes
Body Planes are imaginary flat surfaces that
separate the body or body part into portions.
There are three major planes at right angles to one
another:
Sagittal (midline)
Transverse (horizontal)
Frontal (coronal)

35. Body Planes
A midsagittal section of
the human brain
A frontal (or coronal)
brain section
A transverse (or horizontal)
brain section

36. Body Cavities
◆Embryologically, the human organs develop within
two
major body cavities:
▪ The brain and spinal
cord develop in a
dorsal cavity.
▪ The remaining body
organs are found in the
ventral body cavity.

37. Body Cavities
Cranial cavity is formed by the cranial bones.
Protects the brain
Vertebral canal is formed by bones of vertebral
column.
Contains the spinal cord
Meninges
Layers of protective
tissue that line the
cranial cavity and
vertebral canal

38. Body Cavities
Thoracic cavity is formed by the sternum, ribs, and
the
thoracic portion of the bony vertebral column.
Also called chest cavity
Stabilized by the
internal and external
muscles of the chest

39. Body Cavities
Other cavities are contained within the thoracic
cavity:
Mediastinal cavity
Located in the central part of the thoracic cavity
Left and Right Pleural cavities
Two fluid-filled spaces that surround each lung

40. Body Cavities
◆ Pericardial cavity is itself located within the middle part of
the mediastinal cavity in the thoracic cavity (like a set of
Russian nesting dolls of decreasing size—one placed
inside
the other).

41. Body Cavities
◆ The pericardial cavity is shown here nestled in the
middle mediastinum:
Left
Pleural
cavity
Right
peural
cavity

42. Body Cavities
Abdominopelvic Cavity extends from the diaphragm to
the groin and is encircled by the abdominal wall and
bones and muscles of the pelvis.
Divided into two portions:
Abdominal cavity contains the stomach, spleen, liver,
gallbladder, small and large intestines.
Pelvic cavity contains the urinary bladder, internal organs of
reproductive system, and portions of the large intestine.

43. Body Cavities
Membranes of the body cavities

44. Body Cavities
Other body cavities
Oral (mouth) cavity contains the tongue and teeth.
Nasal cavity is part of the upper airways.
Orbital cavities contain the eyeballs and various nerves
and
blood vessels.
Middle ear cavities contain the small bones of the
middle ear.
Synovial cavities are found in freely moveable joints like
the large joints of the shoulder and hip.

45. Major Body Organs
Cavity Subdivisions Organ Associated
structures
Cranial
Cranium Brain Cranial nerves
Vertebral canal Spinal cord Spinal nerves
Thyroid gland
Thoracic
Pleural Lungs
Mediastinum
Thymus
Esophag
us
Trachea
Superior vena
cava Inferior
vena cava Aorta
Pericardial Heart
Diaphragm
Abdominopelvic
Abdomen
Stomac
h Liver
Small intestine
Large intestine (most)
Greater omentum
Retroperitoneal Kidneys Ureters
Pelvic
Urinary bladder
Ovaries (♀)
Uterine tubes
(♀)
Uterus (♀)
Testes (♂)

46. Major Body Organs
Brain
Spinal Cord
Thyroid
Gland
Thymus

47. Major Body Organs
Lungs
Trachea
Superior vena
cava
Inferior vena cava
Aorta
Heart

48. Major Body Organs
The diaphragm is a powerful skeletal muscle that
divides
the thorax
(thoracic
cavity)
from the abdomen
Diaphragm
(abdominal cavity).

49. Major Body Organs
Trachea
Esophagus
Stomach
Liver
Small
Intestine
Large
Intestine

50. Major Body Organs
Kidneys
Urinary
bladder

51. Major Body Organs
Ovaries
Uterine
tubes
◆Uterus ◆Testes

52. Abdominopelvic Quadrants & Regions
◆Identification of quadrants and regions in the
abdominopelvic cavity helps clinicians describe the
location of the many abdominal and pelvic organs.
◆There are 4 abdominopelvic quadrants and 9 regions.
▪ The dividing lines between these are centered on the
umbilicus (“belly button”).

53. Abdominopelvic Quadrants & Regions
Vertical and horizontal lines pass through the umbilicus
Right upper quadrant (RUQ)
liver
Left upper quadrant (LUQ)
spleen and left kidney
Right lower quadrant (RLQ)
appendix
Left lower quadrants (LLQ)
left ovary ( )

54. Abdominopelvic Quadrants & Regions
◆ Dividing the abdomen and pelvis into regions is done using a
Tic-
Tac-Toe grid. It is a little more complex than using
quadrants,
but is also more specific
There are nine
abdominopelvi
c regions

55. Abdominopelvic Quadrants & Regions

56. Medical Imaging
Techniques and procedures used to create images of
the
human body.
Allow visualization of structures inside the body
Diagnosis of anatomical and physiological disorders
Conventional radiography (X-rays) have been in use
since the late 1940’s

57. Medical Imaging
Radiography is done using X-rays to produce an
image of interior structures. They are inexpensive
and quick
Hollow structures appear black or gray
Do not pass easily through dense structure (bone)
At low dose, useful for soft
tissue (breast)
Mammography (breast)
Bone densitometry
(bone density)

58. Magnetic Resonance Imaging (MRI) is done using an
extremely powerful magnetic field. It is a safe
procedure but cannot be used on patients containing
metal.
Protons in body fluid align with field
Used for differentiating normal and abnormal
tissues (tumors, brain abnormalities, blood flow)
2D and 3D color images can be viewed on a video
monitor.
Medical Imaging

59. Medical Imaging
Computed Tomography or CT-Scans are done using a
computer to organize x-rays to form a 3D image. It
is used to visualize soft tissue in more detail than
conventional radiography.Tissue intensities show varying
degrees of gray.Whole-body CT scans expose the body to a
high dose of x-rays.

60. Medical Imaging
Here are 3 cross sectional images of
a head from the Visible Human
Project. They are done using the
three modalities discussed above.
From top to bottom:
Photograph of frozen, sawed head
CT scan of the same level/plane
MRI scan of the same level/plane
http://vhp.med.umich.edu
/
Objective

61. Medical Imaging
Ultrasound Scanning (sonography) is done using high
frequency sound waves. It is noninvasive and
painless.

62. Medical Imaging
Radionuclide Scanning is done by giving a radioactive
substance (radionuclide) intravenously.
Gamma rays emitted by tissues that take up the
radionuclide are detected by a camera and displayed on a
video monitor.
The color intensity represents the amount of uptake.
Single-photo-emission
computerized
tomography (SPECT) is

63. Medical Imaging
Positron Emission Tomography (PET scan) is done by
injecting a substance emitting positively charged
particles into the body. The collision between positrons
and negatively charged electron in body tissues
produce gamma rays used to form
a computer assisted image.
Used to study physiology of
body structures (metabolism)

64. Medical Imaging
Endoscopy is done using a lighted instrument with a
lens
projecting an image onto a monitor.
Colonoscopy is a study of the interior of the colon.
Laparoscopy is a study of the organs
in the abdominopelvic cavity.
Arthroscopy is a study of the
interior of a joint (knee).

65. Clinical Connection
Noninvasive Diagnostic Techniques are used to inspect
different aspects of the body:
Is often done to access structure and function and to
search for the presence of disease.
Palpation is gently touching body surfaces with hands.
Auscultation is listening to body sounds (stethoscope).
Percussion is tapping on the body surface with fingertips
and listening to echoes.